Bones II

Question 1

Most common bone tumors (2):

Answer 1

• Matrix producing

- Fibrous tumors

Question 2

Most common benign bone tumors (2):

Answer 2

• Osteochondroma

- Fibrous cortical defect

Question 3

Most common malignant bone tumor:

Answer 3

Osteosarcoma

Question 4

Bone tumor hereditary associations (2):

Answer 4

• Li Fraumeni syndrome (p53)

- Hereditary retinoblastoma (Rb mutation)

Question 5

Bone tumors of epiphysis (2):

Answer 5

• Clear cell chondrosarcoma

- Chondroblastoma

Question 6

Bone tumors of diaphysis (2):

Answer 6

• Ewing sarcoma

- Fibrous dysplasia

Question 7

Bone tumors of epiphysis/metaphysis (2):

Answer 7

• Giant cell tumor

- Aneurysmal bone cyst

Question 8

Osteoma (3):

Answer 8

• Subperiosteal or endosteal cortex surface
• Woven and lamellar bone +/- marrow
• May obstruct sinus

Question 9

Gardner syndrome:

Answer 9

Multiple osteomas

Question 10

Osteoid osteoma (3):

Answer 10

• Less than 2cm size
• NSAID relief
• Pain most intense at night

Question 11

Osteblastoma (3):

Answer 11

• Found in vertebrae posterior
• Size greater than 2 cm
• No NSAID relief

Question 12

Osteosarcoma (4):

Answer 12

• Malignant osteoid
• Bimodal age
• Painful enlarging mass
• Codman triangle (tumor lifts periosteum)

Question 13

Most common nonhematopoetic malignant primary bone tumor:

Answer 13

Osteosarcoma

Question 14

Osteochondroma (3):

Answer 14

Exostosis

• Mushroom-shaped cartilage-capped enchodral ossification
• Metaphysis near growth plate of long tubular bones
• Marrow and cortex continuity

Question 15

Chondroma:

Answer 15

Benign hyaline cartilage tumor

Question 16

Enchondroma (3):

Answer 16

• Solitary in metaphysis of tubular bones
• Most common intraosseous cartilage tumor
• Nodules of hyaline cartilage with peripheral enchondral ossification

Question 17

Increased risk for sarcoma transformation (2):

Answer 17

• Enchondromatosis (Ollier disease)

- Maffucci Syndrome: enchondromas with hemangiomas

Question 18

Most common bone tumor of phalanx:

Answer 18

Enchondroma

Question 19

Chondroblastoma is most common in:

Answer 19

Knee epiphyses

Question 20

Two types of chondrosarcoma:

Answer 20

• Clear cell

- Conventional

Question 21

Conventional chondrosarcoma x-ray:

Answer 21

Nodular growth with endosteal scalloping and flocculent densities from calcification
- Reactive thickened cortex bone

Question 22

Clear cell chondrosarcoma (2):

Answer 22

• Teens/young adults

- Epiphysis

Question 23

Fibrous cortical defect (2):

Answer 23

No bone formation

• Small
• Resolve into normal bone

Question 24

Nonossifying fibroma (2):

Answer 24

• Large

- Persist

Question 25

Three patterns of fibrous dysplasia:

Answer 25

• Monostotic
• Polystotic with soft tissue myxomas
• Polystotic with endocrine dysfunction (McCune-Albright sydrome)

Question 26

Monstotic fibrous dysplasia (3):

Answer 26

• Majority
• Teens
• Incidental in most cases

Question 27

Polystotic fibrous dysplasia (2):

Answer 27

• Mazabraud syndrome: soft tissue myxomas

- McCune-Albright syndrome

Question 28

McCune-Albright syndrome (3):

Answer 28

• Cafe au lait skin pigmentations
• Sexual precocity
• Hyperactive G-protein of GNAS gene

Question 29

Fibrous dysplasia (4):

Answer 29

• Well-circumscribed intramedullary
• Large may expand and distort bone
• Gross: tan-white and gritty
• Microscopic: Chinese character woven bone in fibrous stroma

Question 30

Ewing sarcoma gene translocation:

Answer 30

t(11:22): EWS-FLI1

Question 31

Ewing sarcoma/PNET x-ray:

Answer 31

Lytic destruction with onion skin periosteal reaction and sunburst pattern

Question 32

Giant cell tumor of bone (3):

Answer 32

• Most commonly in the knee
• Benign locally aggressive tumor of macrophage/monocyte system
• Epiphyses but may extend into metaphysis

Question 33

Aneurysmal bone cyst (ABC) (2):

Answer 33

• Multiloculated blood-filled cysts

- Metaphysis of long bones and vertebrae

Question 34

Aneurysmal bone cyst x-ray:

Answer 34

Eccentric, expansile and well-demarcated

Question 35

Most common form of skeletal malignancy:

Answer 35

Metastatic disease

Question 36

Majority of skeletal metastasis comes from (5):

Answer 36

• Breast
• Lung
• Thyroid
• Kidney
• Prostate